This invention relates to a self-cooling water container capable of keeping the temperature of the contained water lower than the ambient temperature by utilizing the heat of water vaporization
In dry, hot regions such as the Arabian peninsula, water is supplied for drinking purposes after storing it in a porous ceramic pot or a canteen made of leather or cloth. The stored water is cooled lower than the ambient temperature by utilizing the self-cooling ability of the container. When water is stored in such a container, the water soaks the wall and gradually exudes out to the outer surface of the container. The exuded water is then vaporized taking the heat, through the vaporization process, from the contained water to reduce the stored water temperature to a point lower than the outside temperature.
These conventional self-cooling water containers have many disadvantages. The porous pot is fragile and the outer surface is always wet due to the oozed water. The porous pot as well as the leather and cloth containers become heavy when filled with water, hence, inconvenient to carry. Further, the loss of water due to oozing is fairly large. Impurities in material and dirt (including microbes) adhered to the outside of such containers are dissolved in the exuded water and are transferred back to the interior water, thus giving smells to the water and polluting the water, presenting hygienic problems.
The purpose of the present invention is to provide a self-cooling water container utilizing the heat of vaporization to reduce the interior water temperature to a point lower than the exterior temperature, while overcoming many disadvantages of conventional water containers. The following specific advantages are achieved by this invention:
1. The outside surface of the container remains dry.
2. There is no loss of water due to exudation.
3. No smells or pollution of the inside water occur because no contaminants adhere to the outside contact surface, dissolve or transfer into the inside water across the container wall. Rather, oxygen in the atmosphere easily transfers through the container wall and dissolves into the inside water, hence keeping the water from being putrefied.
4. The container is resistant to tearing and ripping, lightweight, non water-absorbent, flexible so that it can be folded compactly, and convenient to carry due to the dry outside surface.
5. The container, if necessary, can be maintained in a specified, three-dimensional shape by using a perforated backing material such as metal net, punched metal sheet, etc.
6. The preferred interior surface is a smooth, water repellent, continuously porous material and will not allow any adhesion of contaminants, while at the same time allowing for perfect cleaning and sterilization.